Using GraphQL API, I retrieved two days ago an order created at 2019 but into the fulfillment orders array there is an object that was created two days ago. Why this happened?
You will need to share the code that you used to retrieve the order, as well as the details on the object that was created in order to debug why this happened. The first thing that comes to mind is if the code you use to retrieve the order accidentally created the new object.